Automatic station switching



BEST AVMLABLE com Nov. 11 1924. 11,515,260

- 5. G. LEONARD AUTOMATIC STATION SWITCHING Filed Oct. 6 v1922 2 Sheets-Sheet l WITNESSES: INVENTOR if 5mm 6. Leonard.

BESTAVAZLABLE QOPX Nov. 11 1-924.

S. G. LEQNARD AUTOMATIC STATION SWITCHING Filed Oct. 1922 Z Sheets-Sheet 2 F19 E R T-- g Sl ps 3 2 5%;

F 3 x91 x 125 v d I 530m W ow F m T u 3 3 R SN 7 8 0 ..G uw w v G N w- 3 m 3 I TH w @w H G U IT m: 5 g cm am km M i mm i \CFSE WlTNESSESz 0 9 41% ATTORNEY Patented Nov.11 ,-1924.

BEST AVAlLABLE com UNITED STATES. PATENT oFmce.

STUART c. LnoNAnn, QF GALION, on o, AssIcNoR To WESTINGHOUSE ELECTRIC & mtmAcTUnmc comm, A CORPORATION or rmsnvmm.

' AUTomA' Ic sTAj IQN SWITCHING.

Application filed October 6, 1922. Serial n. 592,749.

. f To an whom may concern:

Beit known that I, STUART G. LEONARD, a citizen ofthe United States, and a resi- .dent of Galion, in-thecounty. of Crawford and State of Ohio, have invented a new and useful-Improvement in Automatic Station Switching, of which the following ,is a

specification.

y invention relates to.automatic systerns and particularly to systems employed in controlling the operationof automatic substations.

One object of my invention is to provide an automatic system for controlling the starting of a synchronous converter and the development of predetermined; polarity at the direct-current end to permit the connec tion thereof to the direct-current circuit. j

- Another object'of my invention is to provide a system, of the above-indicated character, in which relatively low starting voltage and'normal operating voltage are consecutively applied to the converter and in which a timing relay is employed to disconnect the converter from thes'ystem if the transfer from starting to running is not made within a predetermined interval of time.

Another object of my invention is to provide a system, of the above-indicated character, in whicha relay is. provided that is responsive to the current traversing the shunt field winding andthat serves to control the connection of the converter to the direct-current circuit when the proper 'degree of excitation obtains -in the field winding.

Another object of my invention is topro vide a system employing the field relay mentioned above *W. ich serves to disconnect the-converter from the system if the circuit of the field winding should become open during operation.

Patent No.'1,435,-229, issued Nov. 14, 1922 .rent side, and the excitation of the shunt field winding is controlled to develop a- .-predetermined polarity at 'the direct-current end after which, transfer is made from starting to runningcondition by applying normal operating voltageto the converter. amope'nding application, Serial No. 584,601, "automatic switching system, filed Aug. 28, 1922 by C. A. Butcher and assigned to the assignee of the present application, means are disclosedand described for introducing an element of time between the opening of the starting switch and the closing of\the running switch of an electrical translating device. In practicing my invention, I utilize the eneral scheme of connectioned application. I. provide a timing device that becomes 'perative as soon as the starting voltage is applied to the converter that serves to disconnect the converter from time interval of the relay setting, the troubleis undoubtedlyofa persisting nature and the timing'device operates to lock out the substation to preclude its automatic restartinguntil the station is inspected and the trouble cleared.

I rovide, also, another protective feature whidh consists of 'a relay that is responsive to the current in the shunt field winding. That relay precludes the connection of the converter to the direct-current 'circuit unless thewinding is sufiiciently energized to permit the-converter totranslate ener from the alternating current circuit to t e direct-current circuit.

tions that, is disc osed in the above-men- The relay also serves as a protective de- I in simplified form, the individual circuits ass-r AVAlLABLE com vice in disconnecting the converter from the system if the field windingshould become starting device associated with the converter tends to actuate the controlling devices to effect the immediate reconnection of the converter to the system. Y

Figure 1 of the accompanying drawings is a diagrammatic view of an electrical system embodying my invention.

Flg. 2 IS a schematic diagram showing,

that control the energization of the respec-. tive operating coils associated with, and controlled by, such circuits.

In referring to the accompanying drawings,'.the main and interlock switches of all of the apparatusare shown in the individual circuits of the schematic diagram in Fig. 2 in the de-energized posit-ion of the control device or apparatus with which the respective switches are associated.

In'the system that is illustrated, energy is received from an alternating current cirunit 1 through a circuit interrupter, or other switching means 2, and a plurality of power transformers 3 by a rotary transformer or synchronous converter 4 which translates such energy into direct-current energy to be thereupon supplied to a direct-current circuit, such as a trolley circuit 5, through a switching device 6.

' When the voltageof the direct-current circuit 5 decreasesto a predetermined value indicating a demand for energy, a voltage relay 8 becomes sufiiciently de-energized to close its switch. The coil of relay 8 is connected between the trolley circuit 5 and ground, as shown in individual circuit A of the schematic diagram. p U

When the demand upon the circuit 5 is manifested by the decrease of voltage and the consequent closing of the relay. switch 8, various control devices,-to be'described later, are operated to'close the main switch 2 and energize the transformers 3. All but two brushes of opposite polarity are then raised from the commutator cylinder by a brush-raising mechanism 9, and a starting switch 10 is then closed to impress a start-. ing voltage of relativelysmall value upon the converter windings to start the converter and accelerate it to sychronous speed. At synchronous speed, the converter develops its polarity at random. If such polarity is a predetermined polarity corresponding to the polarity of the trolley circuit, the starting switch 10 will be opened and a running switch .11 closed to remove the starting voltage and to apply normal operating voltage to the converter. The brush-controlling mechanism 9 is thereupon operated to lower the brushes to the commutator cylinder, after which the converter is connected to the trolley circuit through the switch 6.

If, while the starting voltage is applied to the converter, the latter should develop a. polarity reverse to that of the direct-current circuit, a polarity-responsive relay 12, that is energQzed through the two unraised brushes, would control the reversing of the field winding 13 of the converter bymeans of a field-reversing switch 14. After the converter polarity is reversed and then built.

up in the right direction, the field winding is connected in the proper manner to permit its energization always in the same-direction, after which the transfer is made from starting to running condition.

In order that the degree of excitation of the field winding and of the field-magnetpole members maybe limited when the polarity is developed in the reverse. direction, a resistor 15 is disposed in circuit with the field winding, that is effective while the winding is connected to' the converter brushes in the properma'nner but'which is eliminated from the circuit when the field winding is reversed by the polarized relay to reverse the excitation ofthe field-magnetpole members.

If the polarity is developed in the wrong direction, the resistor 15 is, of course, effective in limiting the excitation only while the polarity is being developed in such wrong direction. If the polarity is developed in the right direction, the resistor 15 is immediately short-circuited during the transfer from starting to running conlition.

A relay 16 is disposed in the circuit of the field winding and is efi'ective to preclude connection of the converter to the directcurrent circuit if the circuit of the field winding should be open and is similarly effective to disconnect the station if the circuit should become open during operation.

(ontrol energy to operate the control apparatus is derived from the alternatingcurrent circuit 1. through an auxiliary transformer 17 and a'switch 18 which isprovided to manually disconnect the station equipment from the source of control energy when it is desired to inspect the apparatus.

Upon referring to individual circuit B of BE T AvAaABLE com 1,515,230 I 3 in its deenergized position, the operating coil of the relay switch 19 and an interlock 20 that is closed whenjthe main. interruptfer 2 is open, to the control bus conductor A single-pole, double-throw, manuallyoperable switch 21 is associated with therelay switch and isadapted, when closed in the -'upper position, to short-circuit the switch 8. The switch21 is closed in its upper position when it is desired to start the station manually and in its lower position when the station .is "ito be automatically started in response to a predetermined voltage condition inthe direct-current circuit 5.

'Upon referringto circuit D, it will be observed that-the operating coil of a rela 22 is energized as soon as the relay switc 19 closes and such circuit may be traced from bus conductor Z through a resistor 23,

theope1 ating'coil of the relay 22, the relay switch 19, a normally-closed neutrallypositioned switch 24 of the. polarized relay 12, a conductor 25, an overspeed device 26 and a conductor 27- to control bus conductor Y. The winding of relay 22: is thereupon.

energized to close its switch. A

The relay switch 22, when closed, comi pletes a circuit E that energizes the operating coil'of a master relay 30 from control bus conductor Y through the operating coilof relay switch 30 to control bus conductor Z, 'The relay 30, when energized, closes threeswitches 31,32 and 33, respectively. Switch 31, when closed, connects the main control bus conductor Z to an auxiliary con- -trol bus conductor X from whichthe control devices operating subsequently thereto are energized. Thus, upon the opening of.

theswitch 31, the control devicesmay be simultaneously and quickly de-energized to disconect the converter from the system.

. Switch 33 of relay 30,When closed, shortcircuits relay switch 19 and the neutrallypositioned switch 24 of the polarized relay,

I more clearly apparent from the circuits D.

thereby maintaining a holding circuit for the relay 22. These circuit relations are and E in the schematic diagram. Relay 22 energizes relay 30, which, in turn, maintains the energizing circuit for relay 22.

Upon referring to the right hand portion of the circuit E, it will be observed that therelay switch 22, when closed, completes a circuit through a raising coil 34 of the brush-control mechanism 9. This circuit may be traced. from bus conductor Z through the switch 22, a conductor 35, an interlock switch 36 that is closed when the running switch ll is open, the raising coil 34' of the brush-operating mechanism, a limit switch 37 and the conductor 27 to the control bus conductor Y. The brush mechanism is thereupon operated to raise all but two of the brushes from the commutator cylinder.

; relay 48 control rupter .2.-

ductor Y through the conductor 27 the interlock switch 38 of the brush-operating mechanism, the operatiirg coil of the. relay 39, an interlock switch 40 that is-closed when the running switch 11 is open, and an interlock switch 41 that is controlled by a transfer relay 42 to the auxiliary busconductor X. The relay 39 is thereupon energized to close three switches 43, 44 and 45, respectively.- A

Switch43, of relay 39,- when closed, completes the circuit G of the operating coil of control relay for the starting switch 10. The circuit maybe traced from the bus con-- a relay 46-from the auxiliary control conductor X, through the switch 43, a resistor 47 and the operating ,coil of the'relay 46'to control bus conductor Y. 'Relay 46 and a The'relay 46 closes its switch to energize the operating coil of relay 48 which circuit may be traced, as seen in the right hand portion of circuit G, from bus conductor X through switch 43, relay switch 46 and operating coil of relay-48 to control bus conductor Y. The relay switch 48, when closed, connects the closing coil 49 ofthe main switch 2 between the main control conductors Y and Z, as shown in circuit H,

whereupon the interru ter 2 is closed.

Since the interrupter 2 is provided with alow-voltage tri coil 51 for holding the in-- terrupter close when the voltage of the circuit 1 is normal, the closing coil '49 may be (lo-energized after the interrupter is closed.

An interlock switch 50, that closes with the main contact members of the interrupter 2, energizes circuit I including the lowv oltage coil 51 of the interrupter 2 and an auxiliary time-element relay 52 which closes its contact members a few seconds after being energized to. short-circuit the coil of the relay 46, as shown in the left portion of circuit G. The relay 46 is thereupon de-e nergized to open its switch, and the relay the closing of the interswitch 48-is thereupon permitted to open,

thereby de-energizing the closing coil of the interrupter 2. v

Simultaneously with the operation of the respective relays, 46 and 48 that eifect the closing of the main interrutper 2, the interlock switch 45 of the relay 39 completes thecircuit including the operating coil of the starting switch 10 toefiect the closing of that switch to apply starting voltage to the converter. This circuit may be traced, as

shown in circuit J, from control bus con- EST AVAILABLE C(jpy ductor Y through conductor 27, the interlock switch 38 of the brush-controlling mechanism, the switch of relay 39 and the operating coil of the starting switch 10 to the tains synchronous speed with the reverse polarity. The starting switch 10, when closing, closes an interlock switch which connects the windings of the polarized relay device 12 across the two unraised brushes of the commutator cylinderof the converter.

This circuit may 'be traced, as shown in the circuit K of the schematic diagram, from the desired positive brush of the converter through conductor 56, a normally closed interlock switch 57 that is closed by the fieldreversin'g switch 14, interlock switch 55 of the starting switch 10, an armature windin '58, and a clutch winding 59 of the polarized relay 12, and a conductor 60 to the desired. negative brush of the converter.

The polarized relay 12, immediately upon being energized, secures the rotating member of the motor to the movable arm 24 by .means of the magnetic clutch coil 59. If the polarity is in the reverse direction, as has been assumed, the movable contaotmember 24 will gradually be actuated'to bridge the contact member 61, whereupon a relay 62, to control the field-switch 14, will be energized, as shown in circuit L, by being con nected directly across the brushes of the converter between the conductors 56 and 60.

The relay 62, when. energized, closes two switches 63 and 64, respectively. Switch 64 completes a holding circuit tomaintain the relay winding connected between the converter brushes so long as the potential difference across the brushes is sulficient to maintain the relay energized to hold the same closed.

The switch 63, when closed, completes the energizing circuit for the operating coil of the reversing switch 14, as shownin circuit M. This circuit may be traced from control the switch .63 of the relay bus conductor Y throu h conductor 27, the, interlock switch 38 oi the brush control mechanism,.the switch 45 of the relay '39,

62 and the operating coil of the field switch 14 to the control bus conductor X. The field winding is thereupon connected to the brushes of the converter commutator in a reverse manner,

thereby reversing the excitation of the fieldmagnetpole members.

As the electromotive force developed by the converter gradually decreases to' zero,

the voltage available to maintain the relay 62 energized decreases until it is insufficient to maintain that relay in its energized position. The switches .63 and 64 are thereupon opened. Switch 63, when open, de-energizes until the correct polarity is developed in theconverter. Normally, however, little difii-- c-ulty is encountered in such reversing operations and,'ordinarily, one reversal is sufficient to reverse the polarity to cause it to be developed in the right direction.

\Vhen the polarity is developed 'in the right direction, the polarized relay 12 actuates the bridging member 24 to engage the contact members 65 which completes the energizing circuit of the operating coil of the transfer relay 42, as illustrated in'circuit N, from control bus conductor Y through switch contact member 65 of the polarized relay and the operating coil of the relay 42 p to control bus conductor X.

A switch 66' is closed when the operating circuit of the operating coil of the control relay 39 for the startingswitch 10, as shown in circuit F. p

The starting switch 10 thereupon opens, and, when in open position, closes an auxiliary interlock switch 68 and opens a switch 69. As is shown in the schematic (ircuit P, the-interlock switch 68, of the starting switch 10, when closed, co-operates with the. interlock switch 67 of the transfer relay 42 to energize the circuit of. a control relay 70 for the running switch 11 by connecting the operating coil between the control bus conductors X and Y. v

The relay 70, when actuated to its energized position, closes two switches 71 and 72; Switch 71,-when closed, connects theoperating coil of the running switch 11 directly to the control bus conductors X and Y, as shown in circuit Q, whereupon the running switch 11 is closed to apply normal operating voltage to the converter windings. The converter is now in proper conditionto.be connected to the direct-current circuit.

In order to permit the converter to build up. or develop its voltage quickly, .the switch 72 of the relay -70 short-circuits the resistor 15 that is connected in series withthe field winding. The limiting effect of the resistor being thus eliminated, the excitation BEST AVAILABLE COPX f the field winding is permitted to increase rapidly.

The brushes of the commutator may now be lowered. The control circuit for effectwhen the main'switchv llis closed, and the switch ofthe relay 22 to the control bus conductor Z; The lowering coil 76 of the brush-control mechanism will, therefore, be

energized to lower the brushes to. the commutator .cylinder, after which the limit switch 75 will be opened.

Whilefthebrushes are being lowered, the

field excitation is being increased until nally such excitation attains a value suflicient to energize and operate the field relay 16-which thereupon closes its two switches 78 and 79. v The switch 78, when closed, ,cooperates, as shown incircuit R, with'an interlock fjgswitch .80 that 'iis closed when the brushesare lowered toithej commutator cvl-.

j m; and the interlock iswitch 32 of the" masters relay 30 to complete an energizing .cireuit for the operating coil of a relay 81 \of the direct-current" to control theclosin I switch '6. The circuit may be traced from bus conductor Y through conductor 27, the.

interlock switch 80 of the brush mechanism,

' the interlock switch 78 of the tield relay 16, the operating coil of relay 81, a conductor 82 and the interlock switch 32 of the master relay 30 to control bus' conductor X. The relay 81 is thereupon energized to close its switch 83.

After the brushes are lowered and the field winding is sufficiently energized, the 3 converter is connected to the direct-current circuit. Switch 83 of the relay 81, when closed, completes the circuit of the operating coil of the directfcurrent switch 6, as shown in schematic circuit R. This circuit may be traced from control bus conductor Y through the operating coil of switch 6, the

switch 83 of the relay 81, the conductor 82 and theswitch 32 of the master relay 30 to the control bus conductor X. 'The switch 6 is thereupon closedto connectthe converter 4 to the direct-current circuit 5.

Switch 6, when closed, closes an auxiliary interlock switch 85. Switch 85, when closed, connects main control bus conductor Z to the auxilia and is connected in parallel relation to switch 31 0f master relay fiOz The switch 85 is larger than the switch1I-r31, and serves to conduct current to the auxiliary control bus conductor X during the continued operation of. thev converter. V

If theidemand should decrease to, or be-' l0w,'a' predetermined value for a predeterswitch 6 is de-energized b ry control .bus conductor .X

mined interval of time, it is desired to shut down the station to obviate the expense of running the machine idl A timing rela 100 is therefore employe which may be ad J'usted to operate at different time intervals 7 from the range of approximately three minutes to one-half hour which serves to disconnect the converter from the system when the demand on the station decreases to a predetermined value for a predetermined in- 7 terval of time corresponding to the setting of the relay. -The operation of this relay may be more readily understood by reference'tov schematic circuit C.- v

The circuit of the operating coil of the timing relay may be traced from the auxiliary bus'conductor W through a conductor 101, the operatingcoil of timing relay 100, the switch 120 of underload relay 90, a conductor 102, an interlockswitch 103 that is closed when the normal-voltage running switch 11 is closed, a conductor 10 1 and the switch 21 in its lower position to the control bus conductor Y. -The switch'120 of the underload relay will be closed only when the current taken from the converter is less than a predetermined value. When timing relay is energized for a predetermined interval of time,'it will-close a switch 105 that may be 95 adjusted for any time interval within the operating range of three to thirty, minutes' 1en the switch '105 ofthe timing relay 100, operating in response to the time and the demand, closes, it affects the disconnec- 100 tion of the converter from the stem by sh'ort-circuiting the operating C01l of the "and de-energize theoperating, coil of the master relay 30 whereupon the auxilia control bus conductor X is disconnected from the us conductor Z by-th switch 31. The. same conductors are then disconnected by the switch 85 of the main direct-current switch 6, since the operating coil of the the opening of switch 32 of the master-re ay 30. This operation is more readily apparentby reference to schematic circ 't. R.

The timing relay 100 is' also provided with an additional element 110 which is emplo'yedasa protective feature during the starting operation of the convert'er to disconnect the converter from the alternating-currentcircuit' and to lock out the contro apparatus "to preclude the auto;

- deemed sufiicient to permit the development Y of a predetermined polarity and the trans- 1 22 by connecting BEST AVAlLABLE COP.-

matic reconnection of the converter until the station is visited by an inspector and the trouble cleared.

The timing element switch 110 is normal 1y adjustedto be, closedafter an interval of approxin'iately one minute to one and onehalf minutes, which interval of time is fer from starting conditions to running conditions by transferring from starting switch 1010 running switch 11. If such transfer is not made within the'interval for which the time-element switch 110 is adjusted, the

switch 110 closes to energize the circuit of a lock-out relay 111 which maintains a short-circuit across the the relay 22 until the hand. K

I he lock-out relay 111,'-when operated, short-circuits the operating coil of the relay the conductors 106 and 107, which may be more readily understood by referring to schematic circuit D.

l/Vhen the transfer from starting to ruin ning conditions is not made within a preoperating coil of relay 111 is reset by determined interval, such condition is nor-- mally indicative of frozen bearings or other trouble that will preclude normal operation of the converter. fore, to prevent entirely any automatic operation of the converter until thestation is at synchronous speed,

I connected to the starting taps of the transformer, a false indication of correct polarity would immediately effect the connection of the converter to the normal operating connections of the transformer. Since the indication of correct polarity was due to.

the electromotive forcethat-was generated from the residual magnetism rather than to thefpolarity of the electromotive force generated by reason of the applied starting voltage, the immediate connection of the converter to the fullevoltage terminals of the transformer might occasion considerable damage to the converter windings.

In order to preclude such immediate application of full operating voltage to the converter, the operation of the lnit-iating and controlling relays .22 and 30 is pre It is desirable, there-I eluded until the field excitation decreases to or below a predetermined value. Thatep' eration is controlled by means of the switch 79 of the field relay l6 and an inter-lock switch 112 of the main circuit interrupter 2 that is closed when the interrupter is op- -ened. Thus, if the interrupter is opened energized and its' while the field relay 16 is switch 79 is maintained closed, the operating coil of the relay 22 will be shortcircuited to preclude its energization until the switch 79 of. the field relay 16 is opened. This operation may be more readily. visualized upon reference to theleft-hand portion of schematic'circuit D.

Overload relays 114 are provided that serve also to energize the lock-out relay 111 when an excessive overload occurs on the alternating-current end of the converter which is suiiiciently excessive to indicate abnormal conditions within the station.

In order to preclude operation'of the converter, under low-voltage, single-phase or reverse-phase conditions, a relay 115 is provided that-isresponsive to any one of such conditions to permit the closure of its switch if any one of such conditions occurs.

The relay 115 also short-circuits the operat-- ing coil of the relay 22 toefiect immediate disconnection'of theconverter from the system. Upon the recurrence of normal conditions, however, the switch opens to permit the re-energization of the relay 22.

By arranging the protective devices to control the energization of the relay 22 according to the faulty condition that occurs, the protective devices may distinguish between temporary persisting faulty conditions to merely disconnect the machine temporarily to maintain such disconnection and preclude the automatic reconnection until the faulty conditions are eliminated.

' By 'means of the timing relay that'is op-' erative until the transfer from starting to running conditions, I effect the disconnection of the converter from the system if the:

transfer it not made within a'predetermined time; The failure to transfer from starting to running conditions within such interval of time is a manifestation of persisting trouble,

and prevent its-automatic restarting until the station is inspected and the trouble cleared.

The field relay which I have provided serves to preclude the connection of the converter' to the direct-current circuit-until the converter is in proper energy-translating condition and serves also to disconnect the converter from the system if the winding should become open-circuited during operation. The relay further. serves to prevent the reconnection of the converter to the 8375-- abnormal conditions and such as frozen bearings. Under such conditions, it .is desirable to lock the station tem after the switching devices have been tating at substantially synchronous speed if,

opened and while the converter is still roa demand for energy should be manifested on the direct-current circuit immediately after the opening of the switching devices, This feature is essential, since a false indication of polarity would be given by the normal operating voltage of the synchronously rotating'machine and the machine .might be connected between the system with its polarity actually developing in the wrong direction. v

I have illustrated merely schematically the operation of the various control de- 'vices and it will, therefore, be understood that changes may be. made in the structure and in the arrangement of the devices without departing from the spirit and scope of my invention, as set forth in the appended claims.v

1 I claim as my invention:

1. In an electrical distribution system, the combination with an alternating-current circuit, a direct-current{circuit and a synchronous converter t9 be connected therebetween, of means for applying starting voltage to the converter winding from the alternating: current circuit, means for subsequently applying normal operating voltage, means dependent upon the development of a predetermined polarity in the converter for cont-role ling the transfer from starting to running voltage and means for disconnecting'the converter from the alternating-current C11- cuit if the development of a predetermined polarity in tle converter and the subsequent transfer from starting to running voltage larity in are not efiected within a predetermined interval of time.

2. In an electrical distributing system, the combination with analternating-current circuit, a direct-current circuit and a synchronous converter to be connected therebetween, of means for applying a starting voltage to the converter from the alternating-current circuit, means for then controlling the development of a predetermined polarity in theconvertercorresponding to that of the direct-current circuit, means operative after the development of the predetermined postarting-voltage means non-operative and for controlling the application of=normal operatmg voltage to the converter from the al ternatmg-current circuit, and means operative while the converter polarity is being developed during the starting operation to disconnect the converter if such predetermined polarity is not developed within a predetermined interval after' the starting voltageis applied to the converter. I

3. In an electrical distribution system, the

jug-current circuit,

the converter for rendering the cpmb ination with an alternating-current' circuit, a direct-current circuit and a syn- "H ULL;

transfer-controlling means to function.

4'. In an electrical distribution system,the combination with an alternating-current circuit, a direct-current circuit and a synchronous converter to be oonneoted'therebetween, of means for appl ing starting voltage to the converter windings'from the alternatmeans for subsequently applying normal operating voltage means dependent upon the development 0 .a predetermined polarity v in the converter for controlling the transfer from starting to running voltage, and timin means operative only after the cnergization of the startfol starting ing means and. until the energization of the running means for disconnecting the conv verter from the alternating-current circuit, if the transfer from starting to running voltage be not effected within an interval of time corresponding to the time setting of the timing means.

5.- In an electrical distrib'uti rgsystem, the combination with an altelffiifihg-cifirent circuit, a diretcurrent' circ" it and a synchronous converter to be connected therebetween, of means for applyingstarting voltage to the converter windings from the alternating-current circuit, means for subsequently applying normal operating volt-- age, means dependent upon the development of a predetermined polarity in the converter for controlling the transfer from starting to running voltage, timing means. for controlling the startingivoltage means dependent upon the failure of the transfer from starting to running condition and means for controlling said timing means comprising an electromagnetic relay switch and a switch controlled thy the running voltage-applying,

6. In an electrical distribution-system, the combination with an alternating-current circuit, a directecurrent circuit 'and'a synchronous converter .to be connected therebetween, of means for applying starting 'voltage'ito the converter windings from the alternating-current circuit, means for subsequently applying normal operating voltage, means dependent uponthe development of a predetermined for controlling the transfer from starting to running voltage, and a. timing device comprising onemeans' for disconnecting the polarity in the converter thereof to the system.

eesravaaastg a converter from the alternating-current. circuitif the transfer from starting to run- I-ing condition is notmade within a prede '-"I7j termined interval of time after the applicailf-tron' of starting voltage to the converter and another means for isolating the converter combination with an j alternating-current circuit, a direct-current circuit and a s chronous converter to be connected there?- tween, of means forappl ing starting voltage to the converter win ings fromthe al-' 'ternating-current circuit, means for subsequent1y applying normal running voltage,

means connected to the direct-current end 0 ofthe converterfor controlling the transfer from startingto running voltage and means for disconnecting the converter from the alternating-current circuit if such transfer is not made within a predetermined interval of time. I 1 8...The combination with analternatingcurrent circuit, a direct-current circuit and a rotary transformer to be connected there- 'between, of means for applying reduced starting and normal running voltages to thetransformer from the alternating-current circuit,-means connected to the direct-current endof the transformer for controlling the transfer from starting to running voltage and means for disconnecting the transformer from the alternating-current circuit if the transfer is not effected within a predetermined interval of time. d 9. In an electrical distribution system, 40 the combination with an alternating-current circuit, a direct-current circuit and a synchronous converter to be connected therebetween, of means for applying starting voltage to the converter windings from the al ternating-cuirent circuit, means forsubsev I quently applying normal'operating voltage, an auxiliary control circuit energized from .the alternating-current circuit, a timing relay qprov-idedwithtwo switches and means for closing one switch after arelatively short inter-val and for closing the other switch after a relativelylongintervalof energization,means whereby the short-interval switch may control the disconnection bf the converter from -.the system to preclude the automatic reconnection thereof and means whereby the long-interval switch may control the disconnection of the converter from the system but may permit the. automatic reconnection 10. In a power-distribution system, the combination with an alternating-current system, a direct-current system and a rotary trapsformer for translating energy 'between the two systems, of means for consecutively (of time; f f 11; In afpower-distribution system, the 80 applying reduced and normal electromotive forces to the rotary transformer from the alternating-current system, means. connected to the direct-current endof the transformer for controlling the transfer'from application of reduced to normal i electromotive force and means operative before-such transfer to disconnectithetransformer from the system if the transfer be not made within a prede- .termined relatively short interval fa-nd op- ,erative after-the transfer if thelqamount of ner y translated be-less than-a predetermined amount for a predetermined interval combination with an alternating-current system, a direct-current, system and a rotary transformer for translating energy between the two systems, of means for consecutively applying reduced and normal electromotive forces to'th'erotary transformer from the alternating-current system, means for automatically initiating and controlling the ap-' plication of the reduced electromotive force tothe transformer, means responsive to a predetermined condition of the direct-current end of the transformer for controlling the transfer from reduced to normalelectromotive force and means for disconnecting the transformer from the system if the transfer be not made within a predetermined interval of time and for precluding the automatic reconnection to .the alternating-current system, and for also disconnecting the converter from the system if the translation of energy between the two circuits be less than a predetermined value for aipredetermined interval of time after the transfer from reduced to normal electromotive force is effected. I

12. In an electrical system, the combination-with an alternating-current circuit, a direct-current circuit and a synchronous converter for translating energy therebetween.

or relay-controlled means operative in a predetermined sequence for controlling the development of a predetermined polarity and the connection of the converter between the two circuits, in which sequence the respective means are dependent for their operation only upon the completion of the operation of the preceding means in said sequence and a timing means for disconnecting the converter from the system if. two

predetermined relay-controlled meansare not. operated within a predetermined inter-- val of time. y V 1?. In an electricalusystem, the'combina' tion with an alternating-current circuit, a direct-current circuit and a synchronous converter for translating energy therebetween, of relay-controlled means operative in a' predetermined sequence for controlling the- I development of a predeterminedclarity and the connection of the converter Between v direct-current circuit and a synchronous con-;

Yerter for translating energy therebetween, of relay-controlled means operative in a predetermined sequence for controlling the development of a predetermined polarity and the connection ofsthe converter between the two circuits, in which sequence the respective means are dependent for their operation only upon the completion of the operation of the preceding means in said sequence, a master relay operative early in the sequence for controlling the energization of the relay-controlled means subsequently operative, and means dependent upon a predetermined faulty condition in eitherthe converter or the relay-controlled means for rendering the masterrelay ineffective.

15. In an electrical system, the combination'with an alternating-current circuit, a direct-current circuit and a synchronous converter for translating energy therebetween, of relay-controlled means operative in a predetermined sequence for controllingthe development of a predetermined polarity and the connection of the converter between the two circuits, in which sequence the respective means are dependent fortheir operation only upon the completion of the operation of the preceding means in said sequence, a master relay operative early in the sequence for controlling the energization of the relay-controlled means subsequently to its operation, means for automatically initiating and controlling the energization of the master relay to render it effective in response to a predetermined condition, and meansfor selectively controlling the master relay to render it ineflective upon the occurrence of a temporary abnormal condition whereby the transformer is disconnected from the system but may be automatically reconnected thereto, and for so controlling the master relay upon the occurrence of a persisting abnormal condition that the conrerter is disconnected from the system and precludedfrom being reconnected to the system by the automatic initiating means.

4 16. In an electrical system, the combination with an alternating-current circuit, a-

direct-current circuit-and a synchronous con verter for translating energy therebetween,

BEST AVAILABLE GDP:

of relay-controlled means operative in a predetermined sequence for controlling the development of-a predetermined polarity and the connection of the converter between the two circuits, in which sequence'the respective means are dependent for their operation only upon the completion of the operation of the preceding means in said sequence, a master relay operative early in the sequence for controlling the energrzutron' of the" re'Iay -TJ controlled means subsequently to its operation, means for automatically initiating and controlling the energization of the masterrelay to render it efiective in response to a predetermined condition, and means for sclectively controlling the master relay to render itmomentarily ineffective upon the occurrence of transient abnormal conditions but yet operable by the automatic initiating and controlling means and also for re'n'der ing the master relay inefi'ective and nonoperable by the automatic initiating and'controlling 'means upon the occurrence of per-v sistent faulty conditions.

-17. In an electrical system, the combination with an alternating-current circuit, a direct-current circuit and a synchronous converter for translating energy therebetween, of relay-controlled means operative in a predetermined sequence for controlling the development of a predetermined polarityv and the connection of the converter between the two circuits, in which'sequence the respective means are dependent for their operationonly Y upon the completion of the operation of the preceding means in said sequence, a master relay operative early in the sequence for controlling the energization of the relaycontrolled' means subsequently operative, and a lockout switch for controlling the master relay to render it ineffective and to preclude asubsequent operation thereof upon the occurrence of a lasting faulty condition until such condition is eliminated.

18. In an electrical system, the combination with an alternating-current circuit, a direct-current circuit and a synchronous converter for translating energy therebc tween, of relay-controlled means operative in a predetermined sequence for controlling the development of a predetermined polarity operation of the preceding means in said sequence, of means selectively responsive to only predetermined faulty conditions in the converter or in the relay-controlled means for rendering such relay-controlled means ineffective until such selective means is sub BEST AVAiLABLE COP.

chronous converter for translating energy therebetween, of means for starting the converter, controlling the development of a predetermined polarity and then connecting the predetermined conditions and protective converter between the two circuits, means for automatically initiating the operation of said starting and controlling means under means for selectively controlling the automatic initiating means to render. the same inefi'ectlve temporarily upon the occurrence 7 of transient abnormal conditions and to the same and to permit the development of chance polarity at the direct-current end, means comprising a relay responsive to the value of the direct-current electromotive force generated by the converter and a relay responsive to the polarity of such electro- -motive force for controlling the develop-.

ment of a predetermined polarity in the converter by controlling the direction of excitation of the shunt field winding and efiecting the ultimate connection of the shunt field winding to the converter always in the same manner, and means subsequently controlled by the polarity-responsive relay after the development of-the predetermined polarity for removing the reduced electromotive force and controlling the application of normal operating electromotive force to the converter.

'21. In a power-distributing system, the

combination with an alternating-current circuit, a direct-current circuit and a synchronous converter for translating energy .therebetween provided with a shunt field winding, of means for impressing areduced electromoti've force on the converter to start the same and to'permit the development of chance polarity at the direct-current end,

and means comprising a -relay responsiveto the value of the direct-current electro-motive force generated by the converter and a relay responsive to the polarity of such electromotive force for controlling the development of a predetermined polarity in the converter .bycontrolling the direction of excitation of the shunt field winding while the converter is subjected to the reduced electromotive force. I Y

22. The combination with an alternating current circuit, a direct-current circuit and a synchronous converter to be connected therebetween and provided with a shunt field winding, of means for applying startingand normal operating voltages to the converter,

means for subsequently connecting the'converter to the direct-current circuit and means responsive 'to the current traversing the field winding for controlling the connection of the converter to the direct-current circuit.

23. The combinationwith an alternatingcurrent circuit, a direct-current circuit and a synchronous converter to be connected therebetween and provided with a shunt field winding, of means for applying starting and normal operating voltages to the converter, means for subsequently connecting the converter to the direct-current circult and means dependent upon the field winding circuit being complete for controlling the connection of the converter to the direct-current circuit.

i 24;. The combination with an alternatingcurrent circuit, a direct-current circuit and a synchronous. converter to be connected therebetween and provided with a shunt field winding, of means for applying starting and normal operating voltages to the converter, means for subsequently connecting the converter to the direct-current circuit and means dependent upon current of a predetermined value traversing the fieldwinding for controlling the connection of the converter to the direct-current circuit.

" 25. The combination withan 'alternatingcurrent circuit, a direct-current circuit and a synchronous converter to be connected therebetween and provided with a shunt 'field Winding, of means for applying starting and normal operating voltages to the converter, means for subsequently connecting the converter to the direct-current circuit, means for rendering said means nonoperative and means for precluding a reapplication of starting voltage to the converter until the generated voltage decreases to a predetermined value.

26. The combination with an alternating current circuit, a direct-current circuit and a synchronous converter to be connected therebetween and provided with a shunt field winding, of means for applying start ing and normal operating voltages to the converter, means for subsequently connect: ing the converter to the direct-current circuit, means'for rendering said means non-operative and means for precluding a reapplication of starting voltage'to the converter until the field current reduces to a predetermined value.

27. The combination with an alternatingcurrent circuit, adirect-currentcircuit and asynchronous converter to be connected therebetween 'and' provided with a. shunt field winding, of means for applying starting and normal operating voltages to the converter, means for subsequently connecting the converter to the direct-current circuit, means for rendering said means nonoperating electromotive forc'cs'to the con-- BEST AVATLABLE COP plying relatively small starting and normal operating electromotive forces to the converter, of means comprising a polarity-re- .sponsive device and a voltage-responsive device for controlling the developn'ientof a predetermined polarity in the converter and then controlling the transfer from the starting to the operating electromotive force.

29. The combination with a synchronous converter and means for consecutively applying relatively small starting and normal verter, of means comprising a polarity-responsive device and a voltage-respons1ve device for controlling the development of a predeterminedpolarity in the converter and means for controlling the transfer from the starting to the operating electromotive force.

30. The'combination with a synchronous converterand means for consecutively applying relatively small starting and normal operating electrolnotive forces to the converter, of means comprising a polarity-responsive device and a voltage-responsive de- -vice for controlling the development of a predetermined polarity in the converter and means for controlling the transfenfroin the starting to the operating electromotive force and means operative after such transfer for rendering the polarity-controlling means non-operative.

31. The combination with a synchronous converter and means for consecutively applying relatively small starting and normal operating .electromotive forces to the converter, of means comprising a polarityresponsive device and a voltage'responsive device for controlling the development of a predetermined polarity in the converter, means for controlling the transfer from the starting to the operating electromotive force and means controlled by the means for applying the normal operating electromotive force to the converter for precluding further operation of the polarity-controlling means after such transfer from starting to operating electromotive force. I

32. The combination with an alternatingcu'rrent circuit, adirect-current circuit and a synchronous converter to be connected therebetween and provided with a shunt field winding, of means for controlling the polarity of the converter by controlling the direction of excitation of the shunt field winding of the converter, comprising switching means having one position for normal direction of field-winding excitation and another position for reversing the lield excitation, means operative as a standard of polarity, having one position when the polarity of the converter is in a predetermined direction corresp mdin; to the polarity of the direct-current circuit and a second position when the converter polarity is reversed relative to that ot' tl1e directcurrent circuit, and avoltage relay operative when the polarity standard means occupies the, position indicating reversed polarity to control-the actuation of the switching means'to the position for reversing the field excitation.

33. The combination with an alternatingcurrent circuit, a direct-current circuit and a syi'ichronous converter to be connected therehetwcen and provided with a shunt field winding, of switching means having-a normal operating position and a reverse operating position for controlling the direc tion of excitation of the field windin to control the development of a predetermined polarity, and a voltage relay rendered fop erative when other than a'predetermined polarity is developed in the converter to actuate the switching means to the reverse operating position and rendered inoperative when the correct polarity is developed, whereby the field winding may then be properly connected to the converter in a predetermined direction. Y

34.. The combination with an alternatingcurrent circuit, a direct-current circuit and a synchronous converter to be connected therebetween and provided with a shunt field winding, of means for connecting the COINGltQI between the two circuits, means for rendering the connecting means nonoperative and means for precluding the reconnection of the converter to the alternating-current circuit until the field current has decreased to a predetermined value.

35. The combination with an alternatingcurrent circuit, a-direct-current circuit and a synchronous converter to be connected therebetween and provided with a shunt field winding, of means for con necting the converter between the two circuits, automatically in response to a predetermined condition in the direct-current circuit, means for disconnecting the converter from both circuits when such condition does not obtain for a predetermined interval of time and means for precluding the reconnection of the converter, upon the recurrence of such condition immediately after the disconnection, until the generated direct voltage of the converter decreases to a predetermined value.

36. The combination with an alternatingcurrent circuit, a direct-current circuit and a synchronous converter to be connected therehetween and provided with a shunt field winding, of means for connecting the converter between the two circuits, auto- BEST AVAiLABLE CCPE both circuits when such condition does not obtain for a predetermined interval of time and means responsive tothe field current for precluding the reconnection of the converter upon the recurrence of such condition immediately after the disconnection, until the generated direct voltage of the converter 10 decreases to a predetermined value.

In testimony whereof, Ivhave hereuntosubscribed my name this second day of October 1922.

STUART G. LEONARD. 

